“Avengers: Age of Ultron” writer/director Joss Whedon admitted his comments about the movie and studio Marvel a year ago were sour, but explained that the end of the production left him feeling “so beaten down” and “like a miserable failure.”

“‘Ultron,’ I’m very proud of,” Whedon told the audience at Tribeca Film Festival, according to Entertainment Weekly. “There are things that did not meet my expectations of myself, and I was so beaten down by the process. Some of that was conflict with Marvel, which is inevitable, but a lot of that was about my own work. And I was also exhausted, and we went right away and did publicity, and I sort of created the narrative, wherein I’m not quite accomplished at it, and people just ran with that: ‘Well, it’s okay, it could be better, but it’s not Joss’s fault.’ And I think that did a disservice to the movie and to the studio and to myself, ultimately. It was not the right way to be, because I am very proud of it.”

And although Whedon is “proud” of the film that has grossed $1.4 billion worldwide, he still admitted that “the things that are wrong frustrate me enormously, and I probably had more of those than I had on other movies I made.”

“But I also got to make, for the second time, an absurdly personal movie where I got to talk about how I felt about humanity and what it means in very esoteric and bizarre ways for hundreds of millions of dollars,” he added. “The fact that Marvel gave me that opportunity twice is so bonkers and so beautiful, and the fact that I come off of it feeling like a miserable failure is also bonkers, but not in a cute way. It becomes problematic.”

Mark Ruffalo, who sat down with Whedon at Tribeca and who plays Hulk in the “Avengers” movies, asked Whedon to take on the next two films in the franchise, but Whedon declined, citing burnout. He took a vacation for the first time in 25 years after “Ultron” hit theaters, and restated his vow to never make another Marvel movie.

Almost a year ago, Whedon told the Empire Film Podcast about a clash with Marvel over certain scenes in the film, “unpleasant” bargaining with the studio over final cuts as well as his disappointment with the movie’s outcome.

Whedon stayed pretty mum on his next project, but did admit that he cried — a lot — while writing it.

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The animosity between Marvel and DC goes back decades in the comics world, but it's still burgeoning in Hollywood. It turns out a bunch of actors have switched sides in that corporate war over the years -- and some are making that move even now.